Heating apparatus



July 9, 1968 w. M. WILSON HEAT ING APPARATUS Filed June 1, 1966 5 Sheets-Sheet 1 A TTORNE Y8 July 9, 1968 w. M. WILSON HEATING APPARATUS Filed June 1, 1966 5 Sheets-Sheet 2 July 9, 1968 w. M. WILSON 3,391,729v

HEATING APPARATUS Filed June 1, 1966 s Shets-Sheet 5 FIG. 5

INVENTOE ATTORNEY-S United States Patent Oflice 3,391,729 a HEATING APPARATUS Warren M. Wilson, 6313 Hollywood Drive,

P811112, Ohio 44129 Filed June 1, 1966, Ser. No. 554,402

Claims. (Cl. 165-39) The present invention relates to heating apparatus and more particularly to an apparatus for heating ronefluid to a pre-determined temperature by another fluid.

It is a primary object of'the present invention to provide a new-and improved apparatus for heating a first fluid by a second fluid and'having means providing a jet action turbulent flow of the first fluid for all velocities thereof to provide for elficient uniform heating thereof by the second fluid. W I

Patented July 9, 1968 provision of an apparatus, as noted in the next preceding object, and wherein the contr'ol means is 'alsoresponsive to the temperature of the water discharged from the apparatus. p

Further objects, novel characteristics and advantages of the present invention will become apparent from the a following detailed description of the present invention Another object'of the present invention is to provide a new and improved apparatus for heating one fluid by another fluid and which is economical to'manufacture and is of adesign in which heating and control units therefor and incorporated into' a compact, integral unit.

A further object of the present invention is the provision of a new and improved apparatus for heating a first fluid by a second fluid and having a heat exchanger through which the fluids are circulated so that heat is transferred from the second fluid to the first fluid along a fixed area of the exchanger and wherein the area of heat transfer between the circulating fluids increases as the demand for the heated fluid increases.

Another object of the present invention is the provision of a new and improved apparatus, as noted in the next preceding object, and wherein the heat exchanger includes a plurality of tubes into which the first fluid is introduced through a plurality of movably mounted tubular distributor members which extend into the tubes in a telescoping relationship and the depth of penetration of the distributor members into the tubes determines the area of heat exchange between the fluids.

A further object of the present invention is to provide a new and improved heat exchange apparatus for heating water by steam and wherein the steam flow is automatically controlled by the demand for heated water and steam flow is shut off during zero flow demand for hot water to prevent overheating of the stagnant water in the heat exchanger. 7

A still further object of the present invention is the provision of a new and improved apparatus as noted in the next preceding object, and wherein the heated'water is discharged from the apparatus at a constant predetermined temperature at which it is to be ultimately used regardless of the duration and quantity of the hot water demand and eliminating the necessity of blending the heated water with cold water before arriving at the destination where it is to be used. 1

Another object of the present invention is the 'provision of a new and improved apparatus for heating a first fluid by a second fluid including a heat exchanger which receives and circulates the first fluid through a plurality of tubes exposed exteriorly to the second fluid so as to transfer heat from the second fluid to the first fluid, the heat exchanger being so constructed and arranged that the tubes are readily tion, repair and replacement;

A further object of the present invention is the provision of a new and improved apparatus for heating water to a predetermined temperature by steam and which includes control means for controlling the application of steam into a heat exchanger in response to movement of a flow sensing member therein and which member moves as the demand for hot water changes.

A still further object of the present invention is the removable for inspecmade with reference to'the accompanying drawings in which: FIG. 1 is a schematic view of a heating apparatus embodying'the present invention;

a FIG. 2 is a sectional-view of the apparatus of FIGzl;

FIG. '3 is a sectional view of a portion of the apparatus disclosedin FIG. 2 and illustrating the controls therefor;

FIG. 4 'is a schernatic view of a modified heating apparatus embodyingthe present invention;

FIG; 5 is a sectional fragmentary view showing a portion of the heating apparatus of FIG. 4;

FIG. "6 is a plan sectional view of the heating apparatus of FIG. 4 taken aproximately along section line 6-6 thereof;

FIG. 7 is a sectional fragmentary view of the apparatus illustrating a'still further modification thereof; and

FIG. 8 is a side elevation of the a further control arrangement.

The present invention provides an apparatus for heating one fluid by another. The apparatus is useful for heating many different fluids, and is particularly useful .in heating water by steam.

As representing the preferred embodiment, a heating apparatus 10 is shown in the drawing for heating water by steam. The heating apparatus 10 includes a heat exchanger 12 which receives the steam and water to be heated by the steam. The steam is delivered to the exchanger 12 by a steam supply conduit. 14. A valve 24 in the steam supply conduit 14 regulates the flow of steam to the heat exchanger 12. Steam condensate is discharged from the exchanger 12 through a steam condensate discharge conduit 16. A steam trap 18 is located in the steam condensate line 16 and in the embodiment of the invention shown in FIG. 1, the steam trap 18 preferably discharges to the atmosphere or a reservoir at atmospheric pressure. The cold water is delivered to the exchanger 12 through a cold water supply conduit 20. A valve (not shown) is located in conduit 20 to regulate the flow of water to the exchanger. The Water heated in the exchanger 12 is discharged through a hot water discharge conduit 22. A valve (not shown) in conduit 22 controls the flow of hot water therethrough and opening of the valve establishes a demand on the exchanger 12 for hot water.

The heating apparatus 10 further includes control means 26 mounted on the heat exchanger 12 and which regulates the steam valve 24 to provide appropriate steam to the heat exchanger 12 to heat the water to a predetermined temperature. The control means 26 sends control signals of variable magnitudes to the steam valve 24 in response to changes in demand for hot water.

The heat exchanger 12 includes a housing or jacket 28, which is preferably cylindrical in cross-sectional configuration. The housing 28 is divided into a steam compartment 30 and a water compartment 32. The housing 28 is formed of two sleeves 28a and 28b which are detachably interconnected. Sleeve 28a defines a part for the steam compartment 30, and sleeve 28b defines part of the boundary for the water compartment 32. The sleeves 28a and 28b are interconnected through a partition or barrier member 34, which may also be referred to as a tube sheet, an which separates the water and steam apparatus illustrating '3 compartments 32 and 30.. The .partition 34 is disposed between the sleeves 28a and,28b in a sandwich-type construction. The periphery of the partition extends beyond the sides of the sleeves and is connected to the respective sleeves through annular flanges 36 and 38 which extend radially from sleeves 28b and 28a, respectively. A seal 34a is inserted between flange 36 and tube sheet 34 and a seal 34b is inserted between tube sheet 34 and flange 38. A radially detachable fastener, such as nut and bolt assemblies 40, extends through aligned openings in the flange 36, the partition 34, and flange 38 and secure these parts in assembled relationship.

The upper end of water chamber 32, as viewed in FIG. 2, is closed by atop cover member 42. The top cover member 42 is bolted to an annular flange 43 on the end of sleeve 28b. A seal 42a is located between member 42 and flange 43. The steam compartment 30 is closed at its bottom end by a bottom cover member 44. The member 44 is bolted to an annular flange 45 on sleeve 28a. A seal 44a is disposed between member 44 and flange 45. The steam compartment 30 is thus a substantially closed compartment except for a steam inlet opening 47 in sleeve 28a which communicates with the steam supply conduit 14 and through which the steam enters the steam comartment 30, and a steam condensate outlet opening 46 in the bottom cover member 44 and seal 44a and which communicates with the steam condensate conduit 16 and through which the steam condensate is discharged from the steam compartment 30.

The water compartment 32 like steam compartment 30 is a substantially closed compartment except for the water inlet opening 48 in sleeve 23b which communicates with the water supply conduit 20 and through which the cold water to be heated enters the exchanger and a hot water oulet opening 50 which communicaes with the hot water discharge conduit 22 and through which the heated water is discharged from exchanger 12.

The water compartment 32 is divided into a cold water reservoir 52 and a hot water reservoir 54 by a piston member 56. The cold water to be heated enters the water compartment 32 through inlet opening 48 into the cold water reservoir 52. The water in cold water reservoir 52 is directed into the hot water reservoir 54 where it is heated by the steam in compartment 30 and is subsequently discharged from the hot water outlet opening 50 into the hot water conduit 22. The hot water reservoir has a variable volume and is disposed beween the upper side of the partition 34 and the lower side of piston 56 as viewed in FIG. 2. A plurality of tubes 58, and in the preferred embodiment six such tubes are shown, are connected at their upper ends to the partition 34 and are supported by the partition. The upper ends of the tubes 58 are open to permit flow of water into and out of the tubes. The opposite or lower ends of each tube 58 is closed by a tube closure member 60. The tube closure member prevents fluid communication between the bottom ends of the tubes 58 and maintains spacing between the tubes. The tubes 58 are ex osed to the steam in compartment 30, and the water to be heated is circulaten through the tubes 58 so that the heat from the steam is transferred through the tubes to heat the water therein. The partition member 34 supports the tubes 58 so that the steam in compartment 30 is prevened from entering the tubes 58 or the water compartment 32 and the tubes are readily removable from the exchanger 12 for inspection and repair or replacement by removing bolt and nut assembly 40.

The cold water is directed from the cold water reservoir 52 directly into the tubes 58 by a plurality of tubular water distributing members 62. In the preferred embodiment, six such tubular members 62 are illustrated. The distributing members 62 are arranged to extend into the tubes 58 in telescoping relationship. The upper ends of the distributormembers 62 are open to communicate with the water in cold water reservoir 52 and are supported for movement as a unit by the water piston 56. The lower end of each of the tubular distributing members 62 has a water discharge orifice 64 for discharging the water from the distributing members 62 into the respective tubes 58. The orifices 64 are designed to direct the water in jet streams into the tubes. The jet action creates turbulence in the water in tubes 58 to provide for uniform heat transfer to the water. In fact, the turbulence occurs at all points in the flow of the water in the heat exchanger. During demand for hot water, the flow of water in the tubes 58 is generally upward from the area at which it is discharged from orifice 64 into the tubes 58 due to the fact that the outlet opening 50 is disposed above the discharge end of distributing members 62. This results in a reversal of the direction of flow of the water, creating and aiding the turbulent jet action flow thereof.

The apparatus 12 is effective to heat the water in the hot water reservoir 32 to a predetermined temperature, regardless of the rate of flow of hot water from the exchanger. To provide for constant tempearture of the discharged water, the area of heat exchanger between the water in tubes 58 and the steam in compartment 30' is variable in accordance with the demand for hot water. Specifically, the greater the demand for hot water, the greater the area of heat exchange provided between the water and the steam. As mentioned previously, the tubular members 62 telescope into the tubes 58 and their depth of penetration therein determines the area of heat exchange between the steam and the water due to the fact that the water outlet opening 50 is disposed above the level of the jet orifices 64. The greater the penetration of the distributor member 62 into the tubes 58, the greater the distance that the water discharged from the orifice 64 must travel in tubes 58 to reach the outlet 50, and consequently the greater the area of heat exchange between the water and the steam. The depth of penetration of the distributor members 62 into the tube 58 is controlled by the reciprocating water piston 56 which supports the distributor members.

The piston 56 moves along sleeve 28b in response to a differential in the water pressures in the cold water reservoir 52 and the hot water reservoir 54. The differential in pressures in the reservoirs is caused by the demand for hot water. The demand for hot water causes water to flow out of the hot water reservoir 54 into the conduit 22 and reduces the water pressure acting on the underside of piston 56. At the same time, the water pressure acting on the upper side of the piston remains substantially the same and, consequently, the piston 56 moves downwardly in the sleeve 28b toward the partition 34. This downward movement moves the ends of the distributor members 62 deeper into the tubes 58. When the demand for hot water is great, the time of exposure of water to the steam is reduced and consequently to provide for constant temperature of the discharged water, the area of heat exchange must be increased to compensate for the decrease in heating time. As described heretofore, this is provided by inserting the distributor members 62 deeper into the tubes 58. Also, the jet action induced by orifices 64 becomes more effective as the pressure differential between chambers 52, 54 increases. This drives the cold water deeper into tubes 58 before reversal of flow takes place and further increases the effective heat transfer area. As the demand for hot water decreases, the pressure acting on the underside of piston 56 causes the piston to move away from seal 34a and is in its neutral position when the demand ceases.

A suitable conventional temperature relief mechanism (not shown) may be disposed in the hot water chamber 32 as a safety device. If during stagnant conditions overheating occurs, a small amount of cold water will be admitted to replace the hot water discharged.

The water piston 56 is biased toward its neutral position, i.e., its position during no water flow or stagnant condition, by a spring 66. Spring 66 acts in concert with the water pressure -1n the hot water reservoir 54 and against the pressure in cold water reservoir 52. The forces acting on the piston 56 aresuch' that the' piston" 56 assumes the neutral position when there is no demand for hot water. The spring 66 also determines the length of piston stroke for a given difference in pressure in the reservoirs 52, 54. The spring 66 is connected to the piston 56 through an actuator rod 68. The'lower end of rod 68 is connected to the water piston by a nut 69 threaded on a threaded end'68a of the rod'68. The rod 68 is guided for axialmovementin opposite directions through the top cover member 42 and seal 42a by a guiding and sealing unit 70. The unit 70 is fixed to the top cover member 42 and the rod'68 extends cent-rally therethrough; A nut 72 is threaded on a threaded stem portion 70a of the guiding and sealing unit 70 and provides a fixed abutment against which one'end'ofspring 66 t H ll The upper end of the control rod 68 extendsthrough the support housing 74a and behind control means26 to provide connection to control lever 80.'-Aflixed to the upper end of control rod 68 is a nut 69b. lnterspaced on control rod 68 between nut 69b and it spring 66 are a washer 69c, connector piece 84, slotted tubular guide piece 76, and top spring seat 78.'Only guide piece 76 is fixed to control rod 68 after spring force has placed all members above the spring into intimate contact. A suitable key (not shown) is fixed in housing 74a, and engages a keyway or slot inguide piece 76. Control rod 68 is adjusted circumferentially until distributor memmembers 62 deeper into the tubes 58. Also the jet action guide piece is locked to control rod 68. Thus, the entire control rod assembly is movable longitudinally,-but guided radially. A suitable linkage (not shown), aflixed lever v80and connector piece 84 together, but permits free movement, so radial movement of lever 80 on control 26 and longitudinal movement of connector piece 84 are permitted in a frictionless manner.

As the water piston 56 is moved downwardly toward the seal 34a in response to a-demand for hot water, the

actuator rod 68 moves with the piston and relative to the guiding and sealing unit 70 causing the abutment member 78--to compress and load the spring 66. When the demand for water is terminated, the .water pressure begins to build up in hot water reservoir 32 and acts with the load spring 66 to move the piston upwardly toward the top cover member 42 against the water pressure in cold water reservoir 52. This action continues' until the pressures have balanced and the Water piston 56 is in its neutral position where it remains until a subsequent demand for water is placed on the unit.

The apparatus also controls the temperature of the discharged water by regulating the flow of steam to the heat exchanger 12. This is accomplished by control means 26 controlling operation of steam valve 24 in accordance with the demand for hot water. The steam valve 24 is commercially available and may be of the nature of a steam valve known in the industry as a Leslie GPK steam valve. The details of construction of steam valve 24 are therefore not shown herein. Suflice it to say the control means 26 for the steam valve 24 to control the steam valve 24 to direct the appropriate steam pressure into the exchanger 12. Movement of the control rod 68 is imparted to the control means 26 by a lever 80.

The lever 80 is fixed at one end to a rotatable shaft 82 and at the opposite end to a connector moved by movement of the rod 68.

A gear 86 (FIG. 3) is keyed on shaft 82 which is also keyed to lever at the opposite end from control rod 68.'Shaft 82 extends through back of control housing 74 to engage lever 80. A second gear 88 is keyed on a shaft 90 and is arranged thereon to mesh with gear 86. The gear 88 rotates shaft 90 which has fixed thereto a c am 92. Cam 92 has a cam. surface 92a designed to provide a desired relationship between the hot water demand and amount of steam delivered to the exchanger. A cam follower 94 is arranged to follow the cam surface 92. The cam follower 94 is rotatably mounted on an end of a range spring lever 96 which moves as the cam follower follows the cam. The range spring lever ;is mounted at the opposite end of a shaft 98. A curved arm 100 is cantilever mounted on the range spring lever 96 and moves with the lever 96.. A range spring 104 is connected at one end to arm 100 by a spring connector 102. The connector 102 is positionable along arm 100 to provide for an increase or decrease in the temperature of the hot water as will be more fully described hereafter. The opposite end of the range spring 104 'is connected to a force balance lever 106 by an adjustable range spring connector 108. The range spring 104 is connected intermediate the end of the forced balance lever 106 which, in turn, is supported at its right-hand end, as viewed in FIG. 3, by a blade spring 110. The blade spring 110 is connected to the housing 74 of the control means 26 and to the end of the force balance lever 106. The blade spring permits displacement of the lever 106 in opposite directions in response to slight pressures acting thereon.

Downward movement of the water piston 58 and actuator rod 68, as viewed in FIG. 2, causes a clockwise rotation of gear 86 and a counterclockwise rotation of gear 88. The counterclockwise movement of gear 88 imparts corresponding movement to shaft 90 and the cam 92. The counterclockwise rotation of the cam moves piece 84 and is cam follower 94 and range spring lever 96 to the left,

as viewed in FIG. 3, exerting a downward force on range spring 104 tending to expand the spring. Downward movement of range spring 104 moves the forced balance lever 106 downward and which downward movement is used to actuate a pilot valve indicated generally 'as 112.

i The free end of the forced balance lever 106 has a threaded member in the form of a bolt 114 which projects from the lever 106 toward the pilot valve 112 and terminates in a conical-shaped nose portion 114a. The extent of projection of bolt 114 from the lever 106 can be adjusted by adjusting a lock nut 116 along the stem of bolt 114. The pilot valve 112 controls the application of control fluid; in the preferred embodiment water is utilized as the control fluid to control the setting of steam valve 24.

The pilot valve 112 has a valve body 118 which is closed at one end by a valve body cap 120. A flexible diaphragm 122 extends across the valve body 118 and is secured in place by the valve body cover member 120. The diaphragm prevents fluid in the valve body from escaping through the valve body cap 120. A threaded has a conical-shaped recess 1240 'which mates with the conical-shaped end 114a of the bolt 114.

Abutting against the underside of the bolt he'ad 124a is an inverted T-shaped tu'bular nozzle 128 which is supported for reciprocation centrally of the valve body 118 by a jam nut 130. The jam nut is threadedly received in an internally threaded portion 130a in the valve housing 118. By appropriate adjustment of the jam nut, the extent of upward movement of the nozzle 128 can be set. The jam nut is fixed against rotation in an adjusted position by a threaded fastener 132. The fastener 132 extends through clamping member 133 and into a threaded opening 132a provided in the body 118. R- tation of the fastener 132 causes the clamping member 133 to engage the jam nut and prevent rotation thereof during operation of the valve 112.

The valve body 118 has an inlet passageway 134, an outlet passageway 136 and an intermediate passageway 138 which communicates the inlet passageway 134. with the outlet passageway 136. A pilot valve member 140 controls the flow of fluid through the intermediate passageway 138. The valve member 140 opens and closes by moving out of and into engagement with a valve seat 138a provided by a portion of the valve body 118 defining intermediate passageway 138. When the valve member is in a closed position, flow between the inlet and outlet passageways is blocked. The valve member 140 is supported intermediate the ends of a pilot valve stem 142. The upper end of the stem 142 abuts against the underside of the nozzle 128 and the lower end thereof is guidably received in an end plug nut 144 which closes the bottom of the housing 118.

The pilot valve member 140 is biased toward its closed position by a spring 146 which surrounds the lower end of the pilot valve stem 132 and acts between the nut 144 and the underside of the pilot valve member 140. The valve member 140 is moved out of seating engagement to an open position by the nozzle 128 moving downwardly, as viewed in FIG. 3, as a result of pressure exerted thereon by the force balance lever 106 and bolts 114 and 124.

The pilot valve inlet passageway 134 is connected to a fluid inlet pressure line which, in the preferred embodiment, is a water line 148 connected to the exchanger water supply line 20. The water line 148 has a conventional water pressure regulator 149 disposed therein and operates to direct a predetermined constant pressure of water to the pilot valve 112.

The pilot valve outlet passageway 136 is connected to a water conduit 150 which directs a controlled water pressure to the steam valve 24 to operate the valve as will be described more fully hereafter. Disposed intermediate the outlet passageway 136 and the conduit 150 is a conduit coupling 152 which is in the nature of a T and connects a control water conduit 154 to the outlet passageway 136. The opposite end of the control conduit 154 is connected to a pressure sensing device, preferably a bellows device 156 connected to exert a force on the underside of the force balance lever 106, and acts against the range spring 104.

The control means 26 operates to control the amount of steam delivered to the exchanger 12 by regulating the steam valve 24 in response to the demand for hot water. When the valve in the hot water outlet line 22 is open, thereby creating a demand for the hot water, the hot water in exchanger 12 flows out of the outlet passage into the outlet conduit 22. This flow of water reduces the pressure in the hot water reservoir 32 causing the water piston 56 and the distributor members to move downwardly in the jacket 28. This downward movement increases the area of the tubes 58 to which the water is exposed, thereby increasing the area of heat exchange between the Water and the steam, as described heretofore. The downward movement of piston 56 also causes a corresponding downward movement of connected control rod 68 which moves the force balance lever 106 downwardly an amount proportional to the extent of movement of piston 56.

The downward movement of the forced balance lever 106 moves the pilot valve member to its open position by moving the bolts 114 and 124, nozzle 128, the pilot valve stem 142 and pilot valve member 140 downwardly. This movement of the pilot valve 140 opens the intermediate passageway 138 and communicates the inlet passageway 134 with the outlet passageway 136 of the pilot valve112. Opening of the valve 112 establishes flow of water from water line 148 through inlet passageway 134, intermediate passageway 138, outlet passageway 136 and into the Water conduit 150. The water in outlet passageway is directed to one side of a diaphragm actuator for the steam valve 24. The steam in steam supply line 14 is directed to the other side of the diaphragm. When a differential occurs in the pressures acting on opposite sides of the diaphragm valve 24, the steam valve 24 is moved to a setting which varies the steam delivered to the exchanger 12. When a static or zero flow condition exists in heat exchanger 12, the steam valve 24 is shut off providing no steam flow through conduit 14. The steam valve 24 opens when the pilot valve 112 directs water through conduit 150 to the diaphragm.

The water pressure established in the outlet conduit 150 by pilot valve v112 corresponds to the demand for hot water. The same pressure is also established in the conduit control line 154 to the bellows 156 and acts on the underside of the bellows 156 to counteract the effect of range spring 104 which is exerting a downward force on the force balance lever 106. When the pressure in line 150 reaches the appropriate value as determined by the cam 92, pilot valve 112 closes and traps the established pressure in line 150 acting on the diaphragm of steam valve 24. The pilot valve closure is produced by spring 146. Spring 146 moves valve member 140, valve stem 138, nozzle 128 and bolt 124 upwardly until valve member 140 seats in valve seat 138a. The upward movement of the parts is permitted by upward movement of lever 106 caused by pressure in control conduit 154 expanding bellows 156. The movement of lever 106 is against the biasing effect of range spring 104. This setting of the control mechanism for the pilot valve 112 thus establishes a control water pressure in conduit 150 for the steam valve 24 and maintains the pressure acting on the diaphragm of valve 24 until the demand for hot water changes.

When the demand changes by closing the valve in hot water outlet line 22, the control means 26 preferably closes steam valve 24 so that no steam is permitted to flow to the exchanger 12. When the demand terminates the pressure builds up in the hot water reservoir 32 and this pressure in conjunction with the spring 66 moves the water piston 56 to its neutral position producing a corresponding upward movement of control rod 68. The upward movement of the control rod causes a clockwise rotation of the cam 92 and a corresponding clockwise rotation of the range spring lever 96 which reduces the pressure exerted by the range spring 104 on the lever 106. As stated previously, at this time the appropriate water pressure is trapped in line 150 and valve member 140 is closed. The water pressure in the outlet passageway 136 acts on the underside of head 124a and the water pressure in the bellows 156 acts against the reduced biasing effects of spring 104 causing the bolt and diaphragm to separate from the upper end of the nozzle. The separation permits the water pressure in the conduits 150, 154 to be vented reducing the pressure acting on the diaphragm of steam valve 24 and permitting the steam valve to close. The relative movement between the nozzle 128 and bolt head 124a is permitted because the nozzle 128 is limited in its vertical movement by the lower end of the jam nut 130.

The vented water is exhausted through a water exhaust port 157 which is connected to a suitable exhaust water conduit not shown. After the pilot valve has exhausted sufficient pressure in the conduit 150 and the pressure acting on bolt head 124a is reduced to an extent that the pressure exerted by range spring 140 on lever 106 causes bolt 114 to move the head 124a of bolt 124 into abutment with the nozzle 128 so that subsequent movement of the water piston 56 imp'arts immediate control movement to the pilot valve member 140. a The control means 26 controls steam valve 24 to direct an appropriate amount of steam through steam supply conduit 14 to the exchanger 12 to maintain the temperaturc of the discharged water constant regardless of the demand for hot water. The constant temperature is provided by the design of the cam surface 92a of the cam niernberDZ, The controlmeans 26 furtherprovides for varying the constant temperature of water discharged from the exchanger. This adjustment is provided by sliding the spring connector member 102along the curved armn100. 'To provide a lower temperature of the water discharged from exchanger 12, the connector member 102 is moved along curved arm 100 to a'position nearer thelrange spring lever 96. This position of adjustment reduces the leverage exerted by lever 96 and spring 104 on the force balance lever 106. To provide for increased water temperature,'the slide is moved to a selected posi-' tion along curved arm 100 which is to the left of the position illustrated in FIG. 3 thereby increasing the leverage applied on the force balance lever 106 by the range spring lever 96. The closer the connector member 102 is positioned to the rfight end of arm 100, the lower the temperature of the discharged water and the closer the member 102 is positioned to the left end of arm 100 the higher the temperature of the discharged water.

The control means 26 described, operates to control the steam valve 24 in response to the demand for hot water. The control means 26 may be controlled by an additional variable control factor. The additional control arrangement which is illustrated in FIGS. 4 and of the drawings operates in response to the pressure in steam condensate line 16. In the description of the embodiment of the invention illustrated in FIGS. 1-3 the condensate pressure was discharged from steam trap 18 to the atmosphere which created no back pressure problems in the steam compartment 30 of the heat exchanger 12. However, in certain systems the condensate pressure line 16 is part of a closed steam system so that back pressure may be created in the steam chamber 30 which would adversely affect the predetermined water temperature. In the control arrangement disclosed in FIGS. 4 and 5, the control means 26' includes, in addition to the structure shown in FIG. 3, a pressure sensing device, preferably a bellows 160, arranged between the upper side of the housing 74 and the upper side of the lever 106. The condensate pressure in the condensate conduit line 16 is communicated to the bellows by a condensate conduit 162. As the back pressure in steam condensate line 16 approaches a pressure which would create an undesirable back pressure on the steam pressure entering the exchanger through the steam conduit line 14, the bellows 160 loads the lever 106 tending to move the lever 106 downwardly to open pilot valve member 140. This downward movement of the lever 106 increases the water pressure acting on the upper side of the steam valve diaphragm which increases the steam pressure delivered to the steam compartment 30. The increased steam flow counteracts the steam condensate back pressure and heats the water to the predetermined temperature. The control means 26' would otherwise comprise the same elements operating in the same manner as disclosed in FIG. 3.

During the period of objectionable condensate back pressure, the water in reservoir 32 has a tendency to be overheated during stagnant, or no-flow condition. Therefore, it is advisable to provide for rate of blending cold water into the hot water to handle minimum flow conditions where piston 56 has barely moved. This is shown duit 22. The flow of cold water through the bypass conduit 164 is controlled by a valve mechanism 166 disposed in the bypass conduit, and is adjusted to produce desired outlet water temperatures at minimum usage conditions. As demand increases, operation of the cam ensues, and steam valve 24 is cam controlled. Further, the percentage ofbypassed cold water becomes less and less a factor of total flow of hot water from the heat exchanger. This bypass arrangement is not necessary where steam condensate discharges to atmospheric pressure. I

j The preferred embodiments of the invention heretofore described assume that'thewat er is delivered to the exchanger through the conduit 20 at a predetermined pressure and at or below a predetermined temperature so that by controlling the amount of steam andthe areaof heat transfer, the water can be heated to a predetermined temperature. However, there are instances where the heating apparatus is utilized in a recircul-atory water system. The present invention further provides a modified control means 26" which is responsive to temperature of the water in hot water outlet conduit 22. The control 26" has particular utility in recirculating water systems and operates to position the force balance lever 106 when the outlet water temperature is above a predtermined value. The temperature responsive control means 26" overrides cam control of the pilot valve 112 and operates to reduce the pressure acting on the diaphragm of the steam valve 24 which, in turn, reduces steam delivered to the exchanger 12. The control means 26" is illustrated in FIG. 8 and includes a temperature responsive device which may be 'a bulb 168 disposed in the outlet water conduit 22. The bulb 168 senses the temperature in conduit 22 and when the temperature exceeds a predetermined amount, the bulb operates to direct a fluid through a line 170 to operate a bellows 172. Bellows 172 is arranged to move a rod 176 upon receiving the fluid. The rod 176 is connected to the force balance lever 106. Upward movement of the rod 176, as viewed in the drawings, moves the force balance lever 106 upward permitting the valve member 140 to close if it is open and permits the bolt head 124a to separate from the upper end of the nozzle 128 to relieve the pressure in the line 150, as described heretofore. This reduces the steam delivered to the exchanger 12 which, in turn, reduces the temperature to which the water is heated. When the temperature of hot water in line 22 returns to the desired temperature, the bulb 168 senses this fact and shuts off the fluid pressure to bellows 172. A spring 178 surrounds a portion of the rod 176 and abuts a stationary rod guide member 180 which is supported by the housing 74 of the control means 26 and functions to guide the rod as it is moved relative thereto. The other end of the spring 178 acts against an abutment member 182 which is connected to move with rod 176. When the rod 178 is moved by the bellows 172, the spring functions to return the rod 176 to its operative control position. The temperature responsive control operates in addition to the operation of control means 26 disclosed heretofore.

The invention further provides means for varying the jet discharges of water from the distributor members 62 and particularly from the orifices 64 therein. The adjustment of the jet flow is accomplished by mounting valve members or rods 182 centrally in the members 62 so that the lower ends 184 thereof which are conical in configuration are disposed adjacent their associated orifice 64. The opposite end of the valve member 182 is threaded and is adjustably connected to the water piston 56 by a fixed perforated nut 186. Turning valve member 182 adjusts the position of the conical nose 184 relative to the orifice 64 so as to control the jet flow stream of water from the distributor member. A suitable plugged opening may be provided in cover member 42 to provide ready access to member 182 for effecting adjustment thereof. As the conical-shaped end 184 moves into the orifice 64 so as to reduce the opening thereof, the pres- 1 1 sure differential across the piston 56 increases. This produces greater movement of piston 56 with the same flow.

It should be apparent from the foregoing that the present invention provides a new and improved heating apparatus for water which is economical to manufacture and is of a design wherein the heat exchanger and controls therefor comprise a single, compact, integrated unit which is effective to accurately control the temperature of the heated water in response to various operating conditions to which the heating apparatus may be exposed. Although the preferred embodiments of the present invention have been described herein in considerable detail, it is intended to cover all changes and modifications thereof which come within the scope of the appended claims.

Having described my invention, I claim:

1. An apparatus for heating a first fluid by a second fluid comprising a heat exchanger having first and second compartments, first fluid inlet means for delivering said first fluid to said second compartment of said heat exchanger, second fluid inlet means for delivering said second fluid to said first compartment of said heat exchanger, an outlet for said first fluid an outlet for said second fluid, said first and second compartments being separated by a plurality of tubes exposed to the second fluid in said first compartment and having one end closed and the other end opening into said second compartment, means forming a part of said heat exchanger and providing a jet action turbulent flow of said first fluid during heating thereof at all velocities of flow of said first fluid, said means providing a jet action turbulent flow of said first fluid comprising a plurality of tubular distributor members, each of said tubular distributor members having one end open and through which said first fluid enters said members and the opposite end thereof having an orifice therein through which said first fluid is discharged therefrom, said orifices being relatively small in size compared to said open ends of said distributor members to provide an increase in the velocity of the fluid in flowing from said distributor members through said orifices, and means supporting said tubular distributor members so that portions of each are disposed within one of said tubes whereby said first fluid is discharged through said orifices into said tubes and provides said jet action turbulent flow.

2. The apparatus defined in claim 1 further including a valve means located in one of said tubular distributor members and operatively associated with the orifice in said one tubular distributor member and adjustable to regulate the flow of said first fluid through said orifice in said one tubular member.

3. The apparatus defined in claim 1 further including a fluid bypass conduit means for directly communicating said first fluid inlet and said outlet and valve means disposed in said bypass conduit means for regulating flow of said first fluid into said outlet.

4. An apparatus for heating a first fluid by a second fluid comprising a heat exchanger having a water chamber and a steam chamber, inlet water conduit means for delivering water to said Water chamber, inlet steam conduit means for delivering steam to said steam chamber, a hot water outlet for delivering hot water from said water chamber, a steam condensate outlet means, a member located in said water chamber and movable therein in response to a change in demand for hot water, valve means in said inlet steam conduit means, and control means for controlling the position of said valve means in response to movement of said member.

5. The apparatus defined in claim 4 wherein said member is a piston supported for movement in said water chamber and having said inlet Water conduit means disposed on one side thereof and said hot water outlet means on the opposite side thereof whereby flow of Water from said water compartment into said hot water outlet means produces movement of said piston.

6. The apparatus as defined in claim 5 further including a plurality of tubular water distributing members supported by said piston and through which said water flows from said one side of said piston to said opposite side, each of said tubular distributing members having an orifice therein through which the water is directed from said distributing members.

7. The apparatus defined in claim 4 wherein said member is a piston supported for movement in said water chamber and having said inlet water conduit means disposed on one side thereof and said hot water outlet means on the opposite side thereof, said piston being moved in said water chamber by a pressure differential between said one side and said opposite side of said piston.

8. An apparatus for heatng a first fluid by a second fluid comprising a heat exchanger having a water chamber and a steam chamber, inlet water conduit means for delivering water to said water chamber, inlet steam conduit means for delivering steam to said steam chamber, a hot water outlet means for delivering hot water from said water chamber, a steam condensate outlet means, a piston supported for movement in said water chamber and having said inlet water conduit means disposed on one side thereof and said hot water outlet means on the opposite side thereof whereby flow of water from said water compartment into said hot water outlet means produces movement of said piston, a plurality of tubular water distributing members supported by said piston and through which said water flows from said one side of said piston to said opposite side, each of said tubular distributing members having an orifice therein through which the water is directed from said distributing members, partition means separating said water chamber and said steam chamber including a plurality of tubes having one end thereof closed and partially defining said steam chamber and the upper end thereof open and adapted to receive said tubular distributing members therein in telescopic relationship, valve means in said inlet steam conduit means, and control means for controlling the position of said valve means in response to movement of said piston.

9. The apparatus defined in claim 8 wherein each of said tubular water distributing members has an orifice therein adapted to direct the water therefrom into one of said tubes and thereby providing a jet action turbulent flow.

10. The apparatus as defined in claim 4 wherein said control means includes means operatively connected to said member and operable in response to movement of said member to send control signals of variable magnitude to said valve means, said control signals increasing in magnitude as the extent of movement of said movable member increases.

11. The apparatus as defined in claim 10 wherein said valve means has a diaphragm actuator, conduit means for directing said control signal to one side of said diaphragm actuator and second conduit means for directing the steam pressure in said inlet steam conduit means to the opposite side of said diaphragm whereby a diflerential in pressure acting on the opposite sides of said diaphragm causes a movement of said diaphragm which movement effects the position of said valve and the amount of steam directed through said steam inlet conduit.

12. An apparatus for heating a first fluid by a second fluid comprising a heat exchanger having partition means defining a water chamber and a steam chamber, a member located in said water chamber and spaced from said steam chamber and movable therein in response to a difference in pressures on the opposite sides thereof, a hot water outlet located between said member and said partition means and providing for a decrease in pressure on one side of a member upon an increase in demand for hot water thereby effecting movement of said member toward said partition means, said member dividing said water chamber into inlet and outlet chamber portions and having means providing for flow between said chamber portions, said member further having a portion which overlaps a portion of said partition means in the direction of move ment of said member with the amount of overlapping increasing with an increase in demand for said first fluid thereby providing for increasing the area of heat exchange between said steam and said water.

13. The apparatus as defined in claim 8 wherein said piston is mounted for movement toward and away from said partition means to vary said telescoping relationship between said tubes and said tubular distributing members to thereby vary the effective heat transfer area of said heat exchanger.

14. An apparatus for heating a first fluid by a second fluid comprising a heat exchanger having partition means defining a water chamber and a steam chamber, a member located in said water chamber and spaced from said steam chamber and movable therein in response to a difference in pressures on the opposite sides thereof, a hot water outlet located between said member and said partition means and providing for a decrease in pressure on one side of said member upon an increase in demand for hot water thereby effecting movement of said member toward said partition means, said member dividing said water chamber into inlet and outlet chamber portions and having means providing for flow between said chamber portions, said partition means including a plurality of tubes having one end thereof closed and surrounded by steam in said steam chamber and the opposite ends thereof open and communicating with said outlet chamber portions, said means providing for flow between said chamber portions including a plurality of tubular distributing members supported by said member and having the lower ends thereof movable into the upper ends of said tubes in a telescoping relationship, the depth of penetration of said tubular distributing members in said tubes increasing said member moves toward said partition means and the demand for said first fluid increases to thereby provide for increasing the area of heat exchange between said steam and said water.

15. The apparatus as defined in claim 14 wherein each of said tubular distributing members has an orifice for directing water into one of said tubes providing a jet action turbulent flow.

16. An apparatus for heating a first fluid by a second fluid comprising a heat exchanger having a jacket, said jacket having separate first and second tubular jacket portions, a partition member disposed between said jacket portions and dividing said jacket into separate chambers, means detachably connecting said jacket portions and said partition member, a plurality of tubes supported by said partition member, each of said tubes having one end open and communicating with one of said chambers and the opposite end closed, first fluid inlet passageway means for directing said first fluid into said one chamber, second fluid inlet passageway means for directing said second fluid into said other chamber, first fluid outlet passageway means for directing said first fluid from said one chamber, second fluid outlet means for directing said second fluid from said other chamber, and piston means having one surface exposed to fluid pressure in said first fluid inlet passageway means and another surface exposed to fluid pressure in said first fluid outlet passageway means and a plurality of tubular distributor members extending into an overlapping relationship with said tubes, said piston means being mounted for movement in said one chamber to vary the eflective heat transfer area between said chambers as a function of .variations in fluid pressure on said surfaces of said piston means by varying the extent of said overlapping relationship between said distributor members and said tubes. 1

17. An apparatus for heating Water by steam comprising a heat exchanger, a water inlet supply conduit for delivering water to be heated to said heat exchanger, a water outlet for delivering heated water from the heat exchanger, a steam conduit for delivering steam to the heat exchanger for heating the water therein, a steam condensate outlet means, fluid pressure operated valve means in said steam conduit for regulating the steam delivered to said heat exchanger in response to a control fluid pressure, and control means for operating said valve means, said control means comprising pilot valve means operable to direct said control fluid pressure to said fluid pressure operated valve means, actuating means for said pilot control valve means including a lever for opening and closing said pilot valve means, means loading said lever for movement in one direction to open said pilot valve means to deliver said control fluid pressure to said fluid pressure operated valve means in response to an increase in demand for said heated water, and a pressure sensing control means operatively connected to said lever and operable to load said lever for movement in a second direction opposite said first direction permitting said pilot valve means to close when said pilot valve means is delivering said control fluid pressure to said fluid pressure operated valve means.

18. The apparatus defined in claim 17 further including a steam condensate conduit for directing steam condensate from said heat exchanger, second. pressure sensing control means operatively connected to said lever and operable to load said lever for movement in said first di rection to open said pilot valve means in response to a predetermined pressure in said steam condensate conduit, and means for directing said pressure in said steam condensate conduit to said second bellows means.

19. The apparatus defined in claim 17 further including temperature responsive means operatively connected to said lever and operable to load said lever for movement in said second direction to effect closing of said pilot valve means in response to a predetermined temperature of the water in said water outlet, and means for sensing the temperature of water in said water outlet and operable to operate said temperature responsive means when the water in said outlet is at said temperature.

20. An apparatus for heating water to a use temperature comprising a heat exchanger, a water inlet conduit for delivering water to be heated to the heat exchanger, a water outlet for delivering heated water at a use temperature from the heat exchanger, a steam conduit for delivering steam to the heat exchanger for heating the water therein, a steam condensate outlet means connected to a steam condensate conduit through which the steam is discharged from said heat exchanger and having a steam condensate pressure therein, valve means in said conduit for controlling the flow of steam to said heat exchanger, a control means for operating said valve means to deliver only the amount of steam to said heat exchanger necessary to heat the water to approximately said use temperature including a sensing means for sensing a difference between the water inlet and outlet pressures, means for positioning said valve means in response to said positioning means to deliver said amount of steam, and means for sensing the pressure in said steam condensate conduit and operable to effect operation of said control means to increase the steam directed through said steam conduit when said pressure exceeds a predetermined value.

References Cited UNITED STATES PATENTS 243,496 6/1881 Braun -142 1,761,035 6/1930 Govers 165-142 2,430,837 11/1947 Tutein 165-39 3,047,274 7/1962 Wilson 165--39 3,232,336 2/1966 Leslie et al. l65--38 ROBERT A. OLEARY, Primary Examiner. CHARLES SUKALO, Examiner. 

1. AN APPARATUS FOR HEATING A FIRST FLUID BY A SECOND FLUID COMPRISING A HEAT EXCHANGER HAVING FIRST AND SECOND COMPARTMENTS, FIRST FLUID INLET MEANS FOR DELIVERING SAID FIRST FLUID TO SAID SECOND COMPARTMENT OF SAID HEAT EXCHANGER, SECOND FLUID INLET MEANS FOR DELIVERING SAID SECOND FLUID TO SAID FIRST COMPARTMENT OF SAID HEAT EXCHANGER, ON OUTLET FOR SAID FIRST FLUID AN OUTLET FOR SAID SECOND FLUID, SAID FIRST AND SECOND COMPARTMENTS BEING SEPARATED BY A PLURALITY OF TUBES EXPOSED TO THE SECOND FLUID IN SAID FIRST COMPARTMENT AND HAVING ONE END CLOSED AND THE OTHER END OPENING INTO SAID SECOND COMPARTMENT, MEANS FORMING A PART OF SAID HEAT EXCHANGER AND PROVIDING A JET ACTION TURBULENT FLOW OF SAID FIRST FLUID DURING HEATING THEREOF AT ALL VELOCITIES OF FLOW OF SAID FIRST FLUID, SAID MEANS PROVIDING A JET ACTION TURBULENT FLOW OF SAID FIRST FLUID COMPRISING A PLURALITY OF TUBULAR DISTRIBUTOR MEMBERS, EACH OF SAID TUBULAR DISTRIBUTOR MEMBERS HAVING ONE END OPEN AND THROUGH WHICH SAID FIRST FLUID ENTERS SAID MEMBERS AND THE OPPOSITE END THEREOF HAVING AN ORIFICE THEREIN THROUGH WHICH SAID FIRST FLUID IS DISCHARGED THEREFROM, SAID ORIFICES BEING RELATIVELY SMALL IN SIZE COMPARED TO SAID OPEN ENDS OF SAID DISTRIBUTOR MEMBERS TO PROVIDE AN INCREASE IN THE VELOCITY OF THE FLUID 